The long term objective of this project is the design of liposomes which can be employed clinically as carriers for anti-tumor agents. Within this framework we are conducting a systematic study of the factors that influence the uptake of liposomes by a normal and transformed cell pair, namely 3T3 and SU 101 3T3 and also L1210. The thesis of this proposal is that such studies can provide information on how to modify the liposomal membrane to achieve preferential uptake by the transformed cell line.